In blood pressure measuring systems as now employed there is a great need to ensure that all the components of the system are operating properly. In particular, in systems of the type using an inflatable cuff it is necessary to determine, independently of use on a patient, how well any individual cuff operates, and if there are any defects, such as leakage, clogging, excessive stiffness, or the like. Thus far, no satisfactory apparatus is available for determining how much pressure from the cuff is being delivered to the surface of an appendage such as a human arm or an animal limb. Once the pressure transmission characteristics of a cuff are known, then its calibration curve can be used to provide a better determination of blood pressure.